Read !!! All !!! Keys that are Pressed

I want to read all keys that are pressed.
With the code i used i read only max 2 keys (Number/Letters/Return/Space/...)
Additional to those 2 keys i can read no more of theses keys. The only keys i am able to read additional are (CTRL(left/right) / ALT(left/right)/SHIFT(left/right)) ...

So how am i able to read a key-combination like (wheather it makes sence or not):
'W'+'A' (moving northwest) +'R' (run quickly) + 'J' (jump)

This is the code i used:
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Ok 4 all who have same problems or are interested in why on many keyboards only 2 keystates can be read:

It is a feature in the hardware. It depends on the keyboards hardware how many pressed keys are recognized. Older keyboards support many keys pressed. In the latest development however (especially on the Laptopsector) only two keypressed are recognized.

There are still keyboards that recognize more ... but do you want to let your customers let buy new keyboards? I don't

To make sure that you cater for all hardware just work around it. Keep a history of what buttons are currently being pressed E.g. if you receive
KeyPressDown J KeyPressDown K with no keypress up in the middle you know the user is pressing both these buttons.